Deleting letter in sign turns it to capitals

Whenever you place down a sign and type in a word, but it's spelt wrong you would usually delete the letter and spell it correctly. But when yousufbakshi delete it, the letter turns to a capital so you have to change it back to lowercase.
1. Place a sign down.
2. Spell a word with the last letter wrong.
3. Go delete the letter and write it again.
4. It is now in capitals.